First test fit complete

[Brian Diehl]

I did my first test fit yesterday of the new powertrain setup.  I was able to validate all my alignments and prove my motor mounts were setup correctly.  However, I also discovered that due to those pesky jake brakes I will need to modify the floor a little bit.  (The jakes make the motor ~ 2" taller.)  I need to get the motor 3 1/4" back more.  Oh well, I'm not giving up the jakes, so the floor has to go.  I didn't see any other clearance issues while I had the engine in.  I was able to get it in and out in one day.  I finished the day by completing the welds on the motor mounts now that I know I don't need to cut them apart and adjust them.  I'm also including a picture of my alternator mount that I finished last week.

[Brian Diehl]

Alternator Mount

[TomC]

Love that Target bag turbo cover!  Good Luck, TomC

[skipn]

Brian,

Looks great!
One silly little question...Why not lower the engine ~2" on the mounts?

Ok maybe two.....Is the air compressor belt driven?

Later
Skip
 

[Brian Diehl]

I'd thought of the lowering ... but I start to have interference issues with the tag axle crossover tube and I'm not wanting to drop the oil pan that much closer to the pavement.  I also will be able to run a standard MCI blower drive belt if I keep the current engine height (same as the detroit at the crank).  I don't expect the floor modification to be that bad.  The main structural strength is up further in the flooring system, which means I'm not going to be modifing large load carring structural members.  I'll need to reinforce around my cut, but I won't need to worry about handling extremely large loads.

The air compressor is gear driven.

[Tom Y]

Brian, Looks good. Do you have a run date on this job? I have put 10 miles on mine, but it is on blocks and still in the garage.  Good luck Tom Y

[Brian Diehl]

I have put 10 miles on mine, but it is on blocks and still in the garage.

LOL !  Thanks for the laugh!

No, no run date scheduled yet.

[MC7S50]

Hey Brian

Your pics remind me of my S50 repower project.  I had to modify the oil pan to get sufficient ground clearance.  Don't give up on the Jakes.  I couldn't do without mine.  I guess the S50 is not as tall, as no floor mods were needed on mine.  What tranny did you decide on? Is your engine electronic?

Write me if you have any questions I may be able to answer.

John

[rv_safetyman]

Hi Brian.  I would call you, but we are out to sea on a cruise that Pat earned. 

Have internet ($$$$$) because I can't give up the bus boards 

Per our phone conversation of a couple of weeks ago, you have done a good job your first belt drive.  Once you start the engine and run it through the spectrum of engine conditions, you will be able to tell if you have any issues.  It looks like you have made the Alt. adjustable, and that is good.  You will want to keep the slack span across the idler such that the tight span does not vibrate and contact it.  I would guess that you will need a bit more clearance than you have now.  The spring loaded idler should provide enough tension for the large generator.  If there is any tension issue, simply make the arc-of-contact on the idler smaller and that will create a geometry that makes the tension higher.  Also , make sure that you have placed the idler arm in a position where the spring is wrapped up enough (I think the idler will have a mark showing the proper rotation).  If you are not sure about slippage, I can run you through some ways to check it.  Do not relay on hearing a screeching noise.   That is big time slip.  These belts are compounded to be quiet and your drive can have slippage and not make noise.  That will really wear the belt.  One way to detect slip is to look for rubber dust, but, again, that only happens with significant slip.

On the v-ribbed belt, alignment is more critical than with V-belts.  The span entering the next sheave is always the most critical.  The span from the crank to the Alt. is long, so you should not have any issue there if the alignment is reasonably good.  The span from the idler to the crank is the most critical, as any idler misalignment will drive the belt out of the grooves.  Your span length is not too bad, but be really sure to check the alignment of the idler.

When you do the AC compressor (if you do), drop me a picture of your mock-up and I will take a look at it.

For you fan drives, I assume you are going to adapt the two stoke pulleys.  The spans there will be quite long and you should not have any issues.

Jim

[Brian Diehl]

Thanks for the comments and thoughts guys...

John, The problem with the Cummins is being a 6 cylinder instead of a 4 cylinder like the S50.  I am running into the floor by 3.25" total (length) ... not even the length of one cylinder.  Thanks for the offer of help.

Jim, Thanks for the thoughts on the belt alignment.  I did the best I possibly could for alignment and hope I got it right.  Time will tell!  On the tensioner I think it is okay as I used the existing old belt off the truck.  So, the belt has already gone through all its stretching.  Also, the idler is smooth... no ribs so the belt should run true from the alt. back to the crank.

On the blower drive and A/C compressor I have a machine shop helping out.  I'm cutting apart the old detroit pulley and running the blower drive off the crank shaft by welding the old fan drive pulley to the existing alt. pulley.  Then I'm welding the original 2 groves worth of A/C compressor pulleys to the existing Cummins accessory drive pulley.  I think it will work great.  The only thing is I will need to find new belts for the new shorter distance from the accessory drive to the A/C compressor.  I haven't done this yet ....